Question

observed by Mendel.
5. (a) For the circuit shown in the diagram, calculate
1) Value of current through the 30 ohm resistor.
(ii) total resistance of the circuit.
(b) Give two advantages of connecting electrical devices in parallel with battery.​

Answer 1

Question 1

i) Current through the 30Ω resistor

→ V = IR ❲ Ohm's Law ❳

→ 6 = I × 30

→ 6/30 = I

→ Current = 0.2 A

ii) Total Resistance through the circuit

→ 1/Rₙₑₜ = 1/R₁ + 1/R₂ .... + 1/Rₙ ❲ Parallel Connection ❳

→ 1/Rₙₑₜ = 1/5 + 1/10 + 1/30

→ 1/Rₙₑₜ = 6/30 + 3/10 + 1/30

→ 1/Rₙₑₜ = (6+3+1)/30

→ 1/Rₙₑₜ = 10/30

→ Rₙₑₜ = 30/10

→ Rₙₑₜ = 3Ω

Question 2

b) Give two advantages of connecting electrical devices in parallel with battery

• Equivalent resistance of the circuit decreases
• If one of the device in the circuit stops working (short circuit) that doesn't affect the working of other devices in the circuit